It's also fairly common for your eyes to exhibit mild signs of a condition known as Graves' ophthalmopathy. In Graves' ophthalmopathy, your eyeballs bulge out past their protective orbit (exophthalmos). This occurs as tissues and muscles behind your eyes swell and cause your eyeballs to move forward. Because your eyes may be pushed so far forward, the front surface of your eyes can become dry. Cigarette smokers with Graves' disease are five times more likely than nonsmokers to develop Graves' ophthalmopathy. This is possibly because smoking inhibits the absorption of anti-thyroid medication that is used to treat Graves' disease.

Graves' ophthalmopathy may cause these mild signs and symptoms:

Excess tearing and sensation of grit or sand in either or both eyes

Reddened or inflamed eyes

Widening of the space between your eyelids

Swelling of the lids and tissues around the eyes

Light sensitivity

Less often, Graves' ophthalmopathy can produce these serious signs and symptoms:

Ulcers on the cornea

Double vision

Limited eye movements

Blurred or reduced vision

Graves' dermopathy

An uncommon sign of Graves' disease is reddening and swelling of the skin, often on your shins and on the top of your feet, called Graves' dermopathy.

In Graves' disease, your immune system mistakenly attacks your thyroid gland, but instead of destroying the gland, an antibody called thyrotropin receptor antibody (TRAb) stimulates the thyroid to make excessive amounts of thyroid hormone.

Your thyroid is part of your endocrine system, which includes a collection of glands and tissues that produce hormones. These chemical messengers coordinate many of your body's activities, from digestion to metabolism to reproduction. Thyroxine — a hormone produced by the thyroid — affects many body systems and is involved in controlling your metabolic rate.

Risk factors

Though the cause of Graves' disease is unknown, researchers believe a combination of factors may determine your likelihood of developing Graves' disease, such as:

A family history of the disease

Sex — Women are seven times more likely to develop Graves' disease than men.

Age — Graves' disease usually develops after age 20.

Stress

Pregnancy

Smoking

Complications

Any time your body produces too much thyroid hormone, because of Graves' disease or another cause, it can lead to a number of complications:

Heart problems. Some of the most serious complications of hyperthyroidism involve the heart. These include a rapid heart rate, a heart rhythm disorder called atrial fibrillation and congestive heart failure — a condition in which your heart can't circulate enough blood to meet your body's needs. These complications are generally reversible with appropriate treatment.

Brittle bones. Untreated hyperthyroidism can also lead to weak, brittle bones (osteoporosis). The strength of your bones depends, in part, on the amount of calcium and other minerals they contain. Too much thyroid hormone interferes with your body's ability to incorporate calcium into your bones.

Thyrotoxic crisis. Hyperthyroidism also places you at risk of thyrotoxic crisis — a sudden intensification of your signs and symptoms, leading to a fever, a rapid pulse and even delirium. This complication is rare, but if it occurs, seek immediate medical care.

Tests and diagnosis

Physical exam. Your doctor examines your eyes to see if they're irritated or protruding and looks to see if your thyroid gland is enlarged. Because Graves' disease increases your metabolism, your doctor will check your pulse and blood pressure and look for signs of tremor. Your doctor will also ask you about your symptoms and your personal and family medical histories.

Blood sample. Your doctor will likely order blood tests to determine your levels of thyroid-stimulating hormone (TSH) and thyroxine. TSH, produced by your pituitary gland, is the hormone that normally stimulates the thyroid gland. In Graves' disease, an abnormal antibody called TRAb mimics TSH, causing elevated thyroxine even while TSH levels remain low. If you have very low levels of TSH and high levels of thyroxine, your doctor may diagnose Graves' disease.

Radioactive iodine uptake. Your body needs iodine to make thyroxine. By giving you a small amount of radioactive iodine and later measuring the amount of it in your thyroid gland, your doctor can determine the rate at which your thyroid gland takes up iodine. A high uptake of radioactive iodine indicates your thyroid gland is producing too much thyroxine, as is the case in Graves' disease. Low uptake occurs in some of the other causes of hyperthyroidism.

Treatments

There's no treatment to stop your immune system from producing the antibodies that cause Graves' disease. Treatments to control the signs and symptoms of Graves' disease are designed to decrease the production of thyroxine or to block its action. Graves' disease treatment includes:

Beta blockers. These medications, which include propranolol (Inderal), atenolol (Tenormin), metoprolol (Lopressor) and nadolol (Corgard), often relieve hyperthyroid signs and symptoms, such as a rapid heart rate, nervousness and tremors. These medications aren't a cure for Graves' because your body will still produce too much thyroxine, but beta blockers block some of the action of the thyroid hormone. Beta blockers are often used in conjunction with other forms of treatment.

Anti-thyroid medications. These prescription medications, including propylthiouracil and methimazole (Tapazole), prevent your thyroid from producing excessive amounts of hormones. Typically, treatment with anti-thyroid medications continues for at least a year. For some people with Graves' disease, treatment with anti-thyroid medications for one to two years causes a long-term remission of the disease. However, relapse is fairly common. These drugs are often used along with radioactive iodine treatment or surgery to help control signs and symptoms. Both drugs can cause serious liver damage, sometimes leading to death. But propylthiouracil has caused far more cases, so it generally should only be used when you can't tolerate methimazole.

Radioactive iodine treatment. To make thyroid hormone, your body needs iodine and uses whatever form of iodine is available in your blood. When you take radioactive iodine, the iodine collects in your thyroid gland, and over time the radioactivity destroys the overactive thyroid cells. This causes your thyroid gland to shrink, and problems lessen gradually, usually over several weeks to several months. Because this treatment causes thyroid activity to decline, you'll likely later need thyroxine treatment to supply your body with normal amounts of thyroid hormones. Treatment doesn't require a hospital stay. Radioactive iodine treatment may increase your risk of new or worsened symptoms of Graves' ophthalmopathy. This side effect is usually mild and temporary, but radioactive iodine therapy may not be recommended if you already have moderate to severe eye problems. After radioactive iodine treatment, any iodine not taken up into the thyroid gland is excreted in your urine and saliva.

Surgery. If you can't tolerate an anti-thyroid drug and don't want to have radioactive iodine therapy, surgery to remove your thyroid gland (thyroidectomy) is an option. After the surgery, you'll likely need thyroxine treatment to supply your body with normal amounts of thyroid hormones. Risks of this surgery include potential damage to your vocal cords and your parathyroid glands, tiny glands located adjacent to your thyroid gland. Your parathyroid glands produce a hormone that controls the level of calcium in your blood. Complications are rare under the care of a surgeon experienced in thyroid surgery.

Treating Graves' ophthalmopathy

If Graves' disease affects your eyes (Graves' ophthalmopathy), you can manage mild symptoms by using artificial tears liberally during the day and lubricating gels at night. If your symptoms are more severe, your doctor may recommend:

Orbital decompression surgery. In this surgery, your doctor removes the bone between your eye socket (orbit) and your sinuses — the air spaces next to the orbit. This gives your eyes room to move back to their original position. Possible complications include double vision and lip numbness.

Eye muscle surgery. The inflammation caused by Graves' disease can affect your eye muscles, making them too short to allow the eyes to align properly. In eye muscle surgery, your doctor cuts the muscle where it attaches to your eyeball and then reattaches it farther back. Sometimes, more than one operation is necessary.

Prisms. You may have double vision either because of Graves' disease or as a side effect of surgery for Graves' disease. Though they don't work for everyone, prisms in your glasses may correct your double vision.

Orbital radiotherapy. Orbital radiotherapy was once a common treatment for Graves' ophthalmopathy. Orbital radiotherapy uses targeted X-rays over the course of several days to destroy some of the tissue behind your eyes. However, some studies have suggested that this treatment provides no benefit for people who have mild to moderately severe Graves' ophthalmopathy. Your doctor may recommend orbital radiotherapy if your eye problems are worsening and prescription corticosteroids alone aren't effective or well tolerated.

Lifestyle remedies

For Graves' ophthalmopathy

These steps may make your eyes feel better if you have Graves' ophthalmopathy:

Wear sunglasses. When your eyes protrude, they're more vulnerable to ultraviolet rays and more sensitive to bright light. Wearing sunglasses that wrap around the sides of your head will lessen the irritation of your eyes from the wind.

Use lubricating eyedrops. Eyedrops may relieve the dry, scratchy sensation on the surface of your eyes. At night, a paraffin-based gel such as Lacri-Lube can be applied.

Elevate the head of your bed. Keeping your head higher than the rest of your body lessens fluid accumulation in the head and may relieve the pressure on your eyes.

For Graves' dermopathy

If the disease affects your skin (Graves' dermopathy), use over-the-counter creams or ointments containing hydrocortisone to relieve swelling and reddening. In addition, using compression wraps on your legs may help.

Coping and support

If you have Graves' disease, make your mental and physical well-being a priority. Eating well and exercising can enhance the improvement in some symptoms while being treated and help you feel better in general. For example, because your thyroid controls your metabolism, you may have a tendency to gain weight when the hyperthyroidism corrects. Brittle bones can also occur with Graves' disease and weight-bearing exercises can help maintain bone density.

Try to ease stress as much as you can, as stress possibly contributes to the development of Graves' disease. Listening to music, taking a warm bath or walking can help relax you and put you in a better frame of mind. Partner with your doctor to construct a plan that incorporates good nutrition, exercise and relaxation into your daily routine.